摘要
The Daweijia wellhead field is located at the coastal karst area in North China. Unsustainable groundwater exploitation in recent decades has found severe seawater intrusion in this area. The results suggest that brackish and saline groundwater is not a simple mixture between seawater and fresh groundwater. Inverse hydrogeochemical model can be used to reveal the main hydrogeochemical reactions controlling the hydro-chemical evolution of coastal karst aquifers in the study area, including the dissolution of calcite, montmorillonite and gypsum, the precipitation of illite and Ca-Na cation exchange with CO2 extrication and there is no dolomitization in this zone.